PSYCHOPHARMACOLOGY
- Neuropharmacology = how we study the effect of drugs on the cells in de nervous
system
- Psychopharmacology = drug induced changes in mood, thanking and behavior
LECTURE 1: NEURAL SIGNALING AND NEUROMODULATION
1. HUMAN NERVOUS SYSTEM
1.1 WHAT IS THE HUMA NERVOUS SYSTEM
- The human nervous system (NS) consists of:
Brain: made up of different parts Vb. Cerebrum, brainstem, diencephalon…
Gyri and sulci to limit brain
Cerebral cortex with pyramidal cells covers tissue
Spinal cord
Peripheral nerves: interaction between nervous system and rest of body
Located in the cortex
It is a typical neuron what you see in the brain
- The brain is an organ that serves as the center of the
NS
4 lobes
Frontal lobe: for word production, problem
solving, planning, behavioral control,
emotion…
Parietal lobe: for sensory awareness, pain
Temporal lobe: for memory, invisible emotion,
word understanding…
Occipital lobe: for vision
Cerebral cortex as outer layer with pyramidal cells
Different section show different parts/areas
1.2 CELLS IN THE NERVOUS SYSTEM
1.2.1 TYPES OF CELLS
- There are 3 types of cells in the nervous system:
Pyramidal cells:
Prominent neuron in cerebral cortex
A lot of branched extensions
Purkinje cells:
Prominent neuron in cerebellar cortex
Glial cells: supporting cells
Astrocytes
Oligodendrocytes (important for neuron firing)
Microglia
Apart from these cells there are also ependymal cells
They don’t have much of a functional role, but they line the cavities in the
ventricles of the brain
Partly in cerebrum, mostly in cerebellum, also in grey nuclei in brainstem and
diencephalon
Different morphology depending on where they are situated
1.2.1.1 ASTROCYTES
- They are not excitable like a neuron, but they have a lot of neurochemical functions
They act to remove access neurotransmitter compounds and they provide
chemicals that sympathize messenger molecules
So they provide the interface between neurons and the blood supply
The brain tissue is highly vascularized and when specific parts of the brain are
, active (when u are stressed/listening to music/…) then the vascularization
differentiate the blood flow within your brain and activates or non-activates
part of the brain
o So there is the sensing activity of the nerve cells and communication with
the bloodcells and this provides the necessary blood flow which
contributes to chemical signaling to transmit and communicate within the
brain
- Astrocytes are old cells that have been found but they are relatively recent explored
- They digest parts of dead neurons
When neurons have died, astrocytes come and digest them
They help cleaning up the brain
1.2.1.2 OLIGODENDROCYTES
- These cells support the electric transmission that happens between neurons
So they build the myeline that is al along certain neuronal axons
Myelinization gives metabolic support and insulates the axons
So the myeline wraps really tight around the axon and then it speeds up
electrical signaling
o Without myeline the electrical signaling is up to 30 times slower
A single oligodendrocyte can extend its process to cover up to 40 axons
The gap in the myeline sheet is called the knot of Ranvier, these helps to speed
up electrical transmission (so it becomes faster)
1.2.1.3 MICROGLIA
- These are growing in popularity in how they are being researched
- These cells are smaller than the other 2 sorts
They have fine little extension that branch out
These cells can be compared with garbage people
To go and remove all the excess material and the components of dead cells,
viral invaders
They are also heavily involved in neuron acclamatory responses
o For example: when you jump in the water there is chance that water comes
up your nose. When the water reach the brain it will start eating and
attacking all the neurons
Then the microglia tries to come and clean it up
1.2.2 CONNECTIONS BETWEEN CELLS
- All nerve cells (neurons) consists of elements:
Cell membrane: has lipid bilayer
Cell body
Dendrites: extensions of the cell body
At the end of the dendrites there will be the synaps
Axon: used to guide nerve impulses away from cell
body
Isolated by myelin sheet
Nodes of Ranvier are openings in myelin sheath where action potentials occur
Synapses: place where one cell contacts other cell
and NT’s are released
Presynaptic nerve terminal and postsynaptic
membrane
Often situated at dendrites of postsynaptic cells
- How does it work?
When there is input in a cell it travels from the axon
terminal down the axon to the dendrites
, In the dendrites will be a chemical reaction and it causes that synaps to fire
o It is called an action potential when it travels down from the cell
o These trigger the synaptic reaction
The chemical reaction is really important because people can design drugs that
act on parts of this system with specificity
2. ACTION POTENTIALS
2.1 RESTING POTENTIAL
- Resting potential is the state of a cell in which the
membrane potential remains stable
Caused by unequal distribution of charged
ions in and out cell
So there is a different charge of ions on
the outside of the cell as on the inside of
the cell
A- ions and K+ ions have higher
concentration in cytoplasm of axon, and
cause inside of cell to be negative
Cl- ions and N+ ions have higher concentration
out cytoplasm of axon, and cause outside of cell
to be positive
Present in all cells of body
Excitable cells use it to form electrical signals
- When cell loses its resting potential it will die
All ion channels open
Calcium can enter cell and causes cell death
All channels open and lets in the ions or let the ions out and this is excitatory of
inhibitory, all these ions can sum up
o If you have a bunch of local potentials, they sum up an you get a big action
potential
o So sometimes it is not just one sharp change, sometimes it’s just little
changes that sum up to be a big change to cause reaction
When you have more negative chargers inside the cell (= hyperpolarization)
When it is hyperpolarized it has to have a refractory period (it need to build up
the ions again)
o When de ions are build up again, the cell can fire
2.2 ACTION POTENTIAL
2.2.1 WHAT IS AN ACTION POTENTIAL?
- Action potential is the state of a cell in which the membrane potential rapidly rises and
falls (explosive depolarization)
Potential-sensitive ion channels pick up differences Vb.
Voltage-gated sodium channels or potassium channels
Net sum of EPSP’s and IPSP’s that cell receives is important:
If it leads to depolarization of cell: opening of voltage-gated sodium channels
If it leads to repolarization of cell: opening of voltage-gated potassium
channels
Process of an action potential:
Resting
Depolarization: Na+ gate opens and goes from
outside to inside of cell
Repolarization: K+ gate opens and goes from
inside to outside of cell
, Hyperpolarization: Sodium-potassium ion pump restores initial distribution
Resting
- A huge amount of energy in our brain goes into making the balance in these ions work
When the brain is deprived of energy (like during a stroke) then the sodium-
potassium pump stomps working in our brain
Out neurons will start dying because they don’t have this balance of the ions
2.2.1.1 DIFFERENCE BETWEEN LOCAL AND ACTION POTENTIAL
LOCAL POTENTIAL ACTION POTENTIAL
Graded All-or-none
Decremental Nondecremental
Spatial and temporal summation Intensity of stimulus coded by rate of
fire
Produced by opening of ligand-gated Produced by opening of vontage-gated
channels channels
Depolarization of hyperpolarization Depolarization
2.2.1.2 EXAMPLE: DRUGS AND TOXINS AFFECTING AXON CONDUCTION
- Drugs and poisons can alter the conduction at the axon
So some drugs are able to alter the conductance along the axon such as local
anesthetics (lidocaine, novocaine,…)
These impair the axonal conduction by blockin the voltage-gated sodium
channel
This means that the channel cant open and the action potential cant occur
o So there for the transmission of a pain signal, in sense of local anestetics,
isn’t communicated to the brain
o So you can numb a part of your body and there is no pain that is
comunicated to your brain
This is why we can have surgery while we are awake
2.2.2 THE PROPAGATION OF AN ACTION POTENTIAL
- In unmyelinated axons
the electrical signals travels slow cause every segment along that axon, or the
membrane, has to be individually depolarized
if you have a really long axon it can take a lot of time to go down the whole
axon
o it has to depolarize the whole axon sequentially and then come all the way
back
- In myelinated axons: allows saltatory transmission
The action potentials are generated only at the nodes of Ranvier
Because myeline insolate the segments in between, the electrical signal jumps
from node to node in a process that is called saltatory conduction
o This makes the conduction much faster, sometimes up to 100 times faster
then unmyelinated axons
This is at the kind of speed that our brain needs to work
- Neuropharmacology = how we study the effect of drugs on the cells in de nervous
system
- Psychopharmacology = drug induced changes in mood, thanking and behavior
LECTURE 1: NEURAL SIGNALING AND NEUROMODULATION
1. HUMAN NERVOUS SYSTEM
1.1 WHAT IS THE HUMA NERVOUS SYSTEM
- The human nervous system (NS) consists of:
Brain: made up of different parts Vb. Cerebrum, brainstem, diencephalon…
Gyri and sulci to limit brain
Cerebral cortex with pyramidal cells covers tissue
Spinal cord
Peripheral nerves: interaction between nervous system and rest of body
Located in the cortex
It is a typical neuron what you see in the brain
- The brain is an organ that serves as the center of the
NS
4 lobes
Frontal lobe: for word production, problem
solving, planning, behavioral control,
emotion…
Parietal lobe: for sensory awareness, pain
Temporal lobe: for memory, invisible emotion,
word understanding…
Occipital lobe: for vision
Cerebral cortex as outer layer with pyramidal cells
Different section show different parts/areas
1.2 CELLS IN THE NERVOUS SYSTEM
1.2.1 TYPES OF CELLS
- There are 3 types of cells in the nervous system:
Pyramidal cells:
Prominent neuron in cerebral cortex
A lot of branched extensions
Purkinje cells:
Prominent neuron in cerebellar cortex
Glial cells: supporting cells
Astrocytes
Oligodendrocytes (important for neuron firing)
Microglia
Apart from these cells there are also ependymal cells
They don’t have much of a functional role, but they line the cavities in the
ventricles of the brain
Partly in cerebrum, mostly in cerebellum, also in grey nuclei in brainstem and
diencephalon
Different morphology depending on where they are situated
1.2.1.1 ASTROCYTES
- They are not excitable like a neuron, but they have a lot of neurochemical functions
They act to remove access neurotransmitter compounds and they provide
chemicals that sympathize messenger molecules
So they provide the interface between neurons and the blood supply
The brain tissue is highly vascularized and when specific parts of the brain are
, active (when u are stressed/listening to music/…) then the vascularization
differentiate the blood flow within your brain and activates or non-activates
part of the brain
o So there is the sensing activity of the nerve cells and communication with
the bloodcells and this provides the necessary blood flow which
contributes to chemical signaling to transmit and communicate within the
brain
- Astrocytes are old cells that have been found but they are relatively recent explored
- They digest parts of dead neurons
When neurons have died, astrocytes come and digest them
They help cleaning up the brain
1.2.1.2 OLIGODENDROCYTES
- These cells support the electric transmission that happens between neurons
So they build the myeline that is al along certain neuronal axons
Myelinization gives metabolic support and insulates the axons
So the myeline wraps really tight around the axon and then it speeds up
electrical signaling
o Without myeline the electrical signaling is up to 30 times slower
A single oligodendrocyte can extend its process to cover up to 40 axons
The gap in the myeline sheet is called the knot of Ranvier, these helps to speed
up electrical transmission (so it becomes faster)
1.2.1.3 MICROGLIA
- These are growing in popularity in how they are being researched
- These cells are smaller than the other 2 sorts
They have fine little extension that branch out
These cells can be compared with garbage people
To go and remove all the excess material and the components of dead cells,
viral invaders
They are also heavily involved in neuron acclamatory responses
o For example: when you jump in the water there is chance that water comes
up your nose. When the water reach the brain it will start eating and
attacking all the neurons
Then the microglia tries to come and clean it up
1.2.2 CONNECTIONS BETWEEN CELLS
- All nerve cells (neurons) consists of elements:
Cell membrane: has lipid bilayer
Cell body
Dendrites: extensions of the cell body
At the end of the dendrites there will be the synaps
Axon: used to guide nerve impulses away from cell
body
Isolated by myelin sheet
Nodes of Ranvier are openings in myelin sheath where action potentials occur
Synapses: place where one cell contacts other cell
and NT’s are released
Presynaptic nerve terminal and postsynaptic
membrane
Often situated at dendrites of postsynaptic cells
- How does it work?
When there is input in a cell it travels from the axon
terminal down the axon to the dendrites
, In the dendrites will be a chemical reaction and it causes that synaps to fire
o It is called an action potential when it travels down from the cell
o These trigger the synaptic reaction
The chemical reaction is really important because people can design drugs that
act on parts of this system with specificity
2. ACTION POTENTIALS
2.1 RESTING POTENTIAL
- Resting potential is the state of a cell in which the
membrane potential remains stable
Caused by unequal distribution of charged
ions in and out cell
So there is a different charge of ions on
the outside of the cell as on the inside of
the cell
A- ions and K+ ions have higher
concentration in cytoplasm of axon, and
cause inside of cell to be negative
Cl- ions and N+ ions have higher concentration
out cytoplasm of axon, and cause outside of cell
to be positive
Present in all cells of body
Excitable cells use it to form electrical signals
- When cell loses its resting potential it will die
All ion channels open
Calcium can enter cell and causes cell death
All channels open and lets in the ions or let the ions out and this is excitatory of
inhibitory, all these ions can sum up
o If you have a bunch of local potentials, they sum up an you get a big action
potential
o So sometimes it is not just one sharp change, sometimes it’s just little
changes that sum up to be a big change to cause reaction
When you have more negative chargers inside the cell (= hyperpolarization)
When it is hyperpolarized it has to have a refractory period (it need to build up
the ions again)
o When de ions are build up again, the cell can fire
2.2 ACTION POTENTIAL
2.2.1 WHAT IS AN ACTION POTENTIAL?
- Action potential is the state of a cell in which the membrane potential rapidly rises and
falls (explosive depolarization)
Potential-sensitive ion channels pick up differences Vb.
Voltage-gated sodium channels or potassium channels
Net sum of EPSP’s and IPSP’s that cell receives is important:
If it leads to depolarization of cell: opening of voltage-gated sodium channels
If it leads to repolarization of cell: opening of voltage-gated potassium
channels
Process of an action potential:
Resting
Depolarization: Na+ gate opens and goes from
outside to inside of cell
Repolarization: K+ gate opens and goes from
inside to outside of cell
, Hyperpolarization: Sodium-potassium ion pump restores initial distribution
Resting
- A huge amount of energy in our brain goes into making the balance in these ions work
When the brain is deprived of energy (like during a stroke) then the sodium-
potassium pump stomps working in our brain
Out neurons will start dying because they don’t have this balance of the ions
2.2.1.1 DIFFERENCE BETWEEN LOCAL AND ACTION POTENTIAL
LOCAL POTENTIAL ACTION POTENTIAL
Graded All-or-none
Decremental Nondecremental
Spatial and temporal summation Intensity of stimulus coded by rate of
fire
Produced by opening of ligand-gated Produced by opening of vontage-gated
channels channels
Depolarization of hyperpolarization Depolarization
2.2.1.2 EXAMPLE: DRUGS AND TOXINS AFFECTING AXON CONDUCTION
- Drugs and poisons can alter the conduction at the axon
So some drugs are able to alter the conductance along the axon such as local
anesthetics (lidocaine, novocaine,…)
These impair the axonal conduction by blockin the voltage-gated sodium
channel
This means that the channel cant open and the action potential cant occur
o So there for the transmission of a pain signal, in sense of local anestetics,
isn’t communicated to the brain
o So you can numb a part of your body and there is no pain that is
comunicated to your brain
This is why we can have surgery while we are awake
2.2.2 THE PROPAGATION OF AN ACTION POTENTIAL
- In unmyelinated axons
the electrical signals travels slow cause every segment along that axon, or the
membrane, has to be individually depolarized
if you have a really long axon it can take a lot of time to go down the whole
axon
o it has to depolarize the whole axon sequentially and then come all the way
back
- In myelinated axons: allows saltatory transmission
The action potentials are generated only at the nodes of Ranvier
Because myeline insolate the segments in between, the electrical signal jumps
from node to node in a process that is called saltatory conduction
o This makes the conduction much faster, sometimes up to 100 times faster
then unmyelinated axons
This is at the kind of speed that our brain needs to work
